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BACKGROUND: Fixation strength of metal and bioabsorbable interference screws has not been evaluated while varying the anterior cruciate ligament graft tension angle. HYPOTHESIS: There is no difference in fixation strength between 2 types of interference screws for anterior cruciate ligament graft fixation while the graft tension angle is varied relative to the femoral tunnel. STUDY DESIGN: Controlled laboratory study. METHODS: Forty-eight anterior cruciate ligament reconstructions were performed using immature porcine femurs stripped of soft tissue and doubled-over porcine flexor digitorum profundus tendon grafts. Specimens were randomized to bioabsorbable or titanium interference screw fixation. Specimens were randomized to one of three pull angles (0 degrees , 30 degrees , 60 degrees ) representing loading at different knee flexion angles (n = 8/group). Reconstructed ligaments were tensioned to 10 N followed by 200 loading cycles between 10 and 150 N and a final failure test. Construct elongation (mm) at 100 and 200 cycles and failure load (N) were analyzed using a 2-way analysis of variance (P < .05). RESULTS: Screw material interacted significantly with graft tension angle, as the bioabsorbable screw specimens demonstrated significantly greater fixation strength when tensioned at greater angles. Specimens fixed with bioabsorbable screws showed significantly less elongation at both 100 and 200 cycles and significantly greater failure load compared with titanium screws. CONCLUSION: Bioabsorbable interference screws acutely have increased fixation strength compared with titanium interference screws for anterior cruciate ligament grafts loaded at greater tension angles. CLINICAL RELEVANCE: The strength of anterior cruciate ligament reconstruction fixation increases with increasing divergence between the tension angle and femoral tunnel, a condition seen when the knee approaches full extension. [ABSTRACT FROM AUTHOR]

Objective: To compare four imaging methods in the evaluation of the postoperative meniscus: conventional arthrography, conventional MR imaging, MR arthrography with iodinated contrast material, and MR arthrography with gadolinium-based contrast material.Design and Patients: Thirty-three patients referred for knee MR examinations with a history of meniscal surgery were studied prospectively. At the first patient visit, conventional MR examination was followed by an MR arthrogram with gadolinium-based contrast material. At the second visit, a conventional arthrogram with iodinated contrast material was followed immediately by an MR examination. Imaging examinations were interpreted by a masked reader, and then compared with the results of repeat arthroscopic surgery in 12 patients.Results: The correct evaluation of the status of postoperative menisci was allowed in 12 of 13 patients (92%) by MR arthrography using gadolinium-based contrast agent, 10 of 13 patients (77%) by conventional MR examination, 9 of 12 patients (75%) by MR arthrography, and 7 of 12 patients (58%) by conventional arthrography.Conclusion: Intra-articular fluid is advantageous in the evaluation of patients with a suspected meniscal retear. MR arthrography with gadolinium-based contrast material is the most accurate imaging method for the diagnosis of meniscal retears. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to illustrate the magnetic resonance (MR) image appearance of the structures of the posteromedial "corner" of the knee with particular emphasis on the anatomy and differentiation between the medial collateral ligament and the posterior oblique ligament.Design: Six cadaveric knee specimens underwent MR imaging, before and following instillation of intra-articular contrast material. The knees were sectioned in the axial, coronal, and coronal oblique planes and the gross morphology of the posteromedial corner and surrounding structures was studied and correlated with the MR images.Patients: The human cadaveric specimens were from two female and four male patients (age at death, 72-86 years; average, 78 years).Results and Conclusions: The contrast-enhanced sequences and the coronal oblique images allowed for improved visualization of the structures. [ABSTRACT FROM AUTHOR]

A developmental anomaly of the long head of the biceps tendon was found in a cadaveric shoulder. Findings on arthroscopy, routine MR imaging, and MR arthrography were compared and correlated with results of anatomic dissection. MR arthrography appears to be a very good diagnostic imaging method for depicting this anomaly prior to arthroscopy. [ABSTRACT FROM AUTHOR]

Background: With the increase in the number of total ankle arthroplasties (TAA), guidelines on when physicians should begin to consider patients' return to driving are valuable. Further, due to sagittal motion strength, the ankle is the most important mover in braking motions over the knee and hip., Questions/purposes: (1) Does brake-reaction time return to a safe value within 6 weeks of TAA? (2) Are there factors associated with a delay of return of brake-reaction time to safe values after TAA?, Methods: After obtaining institutional review board approval for the study, we prospectively recruited 60 patients undergoing right TAA. A large proportion of the patients undergoing TAA during the period were recruited. Patients who had extensive concomitant surgery, such as triple arthrodesis or tibial osteotomy, were excluded from the study. Patients were between 43 and 83 years old (median, 63 years), and 35 (59%) were men. Brake-reaction time was tested at 6 weeks postoperatively and repeated weekly until patients achieved a passing brake-reaction time. A control group of 20 volunteer participants matched for age and sex who did not have right lower-extremity pathology or pain were used to establish a passing brake-reaction time of 0.850 seconds. Patients were given a novel driver-readiness survey to complete; a score of 10 of 15 points or higher was considered a passing score. The following factors were explored for their association with brake-reaction time: age, American Orthopaedic Foot and Ankle Society (AOFAS)-Hindfoot assessment and VAS for pain via a patient-reported survey, and ankle plantarflexion and dorsiflexion via dedicated weightbearing lateral radiographs made with the ankle in maximum plantarflexion and dorsiflexion., Results: At 6 weeks postoperatively, 92% of patients (54 of 59) achieved a passing brake-reaction time and were considered able to drive safely, and the mean brake-reaction time of the patients with a passing brake-reaction time was 0.626 seconds (± 0.111). At 9 weeks, all patients who completed the study achieved a passing brake-reaction time. Patients with a failed brake-reaction time at 6 weeks had greater median VAS scores for pain (3 [interquartile range 2 to 7] versus 1 [IQR 0 to 3]; p = 0.022) and diminished ankle plantarflexion (14° [± 5°] versus 24° [± 10°]; p = 0.037) compared with those with a passing brake-reaction time at that time point. All five patients with a failed brake-reaction time also had a failing score for the driver-readiness survey., Conclusions: More than 90% of patients in this series achieved a safe brake-reaction time within 6 weeks of TAA, and those who did not were more likely to have had more pain and a stiffer ankle. Surgeons might counsel patients with persistent pain and stiffness at 6 weeks to delay driving for an additional 3 weeks, since by 9 weeks after TAA, all patients in this series had a brake-reaction time comparable with patients who had not undergone surgery. Future studies might elucidate what key gaps in knowledge remain and determine a practical way to answer these questions., Level of Evidence: Level II, therapeutic study.

Safe and effective arthroscopic surgery requires ambidextrous motor skills. The current study examined dominant versus non-dominant hand performance on a virtual reality serious game in a group of expert arthroscopic surgeons (n=15) compared to a group of orthopedic surgery residents (n=10). A virtual reality Tetris game was performed with the arthroscopic camera and arthroscope in one hand, using an arthroscopic grasping tool in the opposite hand to manipulate the virtual Tetris blocks onto the game grid. A second run was performed after swapping instruments between hands. The order of hand testing was randomized. There was no statistically significant difference in exercise time, grasper path length, or camera path length between the right and left hands of the expert surgeons. In contrast, there were statistically significant differences in all of these parameters between the two hands for the orthopedic surgery residents, with better performance when the grasping tool was used in the dominant hand. The findings of this study suggest that virtual reality games which incorporate progressive cognitive loading could be used to facilitate training, automation, and objective assessment of surgical motor skills.

Purpose: The purpose of this study was to investigate the use and validity of virtual reality modules as part of the educational approach to mastering arthroscopy in a safe environment by assessing the ability to distinguish between experience levels. Additionally, the study aimed to evaluate whether experts have greater ambidexterity than do novices., Methods: Three virtual reality modules (Swemac/Augmented Reality Systems, Linkoping, Sweden) were created to test fundamental arthroscopic skills. Thirty participants-10 experts consisting of faculty, 10 intermediate participants consisting of orthopaedic residents, and 10 novices consisting of medical students-performed each exercise. Steady and Telescope was designed to train centering and image stability. Steady and Probe was designed to train basic triangulation. Track and Moving Target was designed to train coordinated motions of arthroscope and probe. Metrics reflecting speed, accuracy, and efficiency of motion were used to measure construct validity., Results: Steady and Probe and Track a Moving Target both exhibited construct validity, with better performance by experts and intermediate participants than by novices (P < .05), whereas Steady and Telescope did not show validity. There was an overall trend toward better ambidexterity as a function of greater surgical experience, with experts consistently more proficient than novices throughout all 3 modules., Conclusions: This study represents a new way to assess basic arthroscopy skills using virtual reality modules developed through task deconstruction. Participants with the most arthroscopic experience performed better and were more consistent than novices on all 3 virtual reality modules. Greater arthroscopic experience correlates with more symmetry of ambidextrous performance. However, further adjustment of the modules may better simulate fundamental arthroscopic skills and discriminate between experience levels., Clinical Relevance: Arthroscopy training is a critical element of orthopaedic surgery resident training. Developing techniques to safely and effectively train these skills is critical for patient safety and resident education., (Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

This study was designed to determine which subscapularis repair method performs best under fatigue loading. Fresh-frozen human cadaveric shoulders were used. A standard circumferential release was performed, including a rotator interval release and separation of the subscapularis from the anterior and inferior capsules. One of 3 methods was used to repair the subscapularis tendon: tendon-to-tendon, tendon-to-bone, or bone-to-bone using a buttress plate. The shoulder was mounted on a fatigue-testing machine, and the medial end of the subscapularis tendon was attached to a soft-tissue clamp. We initially tested each specimen for fatigue at 150 N for 500 cycles, then at 300 N for 2500 cycles. The failure rate of bone-to-bone and tendon-to-tendon repairs was significantly better than that of the tendon-to-bone repair. The bone-to-bone repair exhibited the best combination of repair strength and restoration of subscapularis length.

Purpose: To biomechanically compare a novel suture welding method to 2 standard suture materials when tied with 3 types of arthroscopic knots., Methods: Sixty suture loops were tied with Weston, Roeder, and Duncan knots for both No. 2 FiberWire (FW) and No. 2 Ethibond (EB; 10 loops/group). Ten suture loops were created using a novel technique using No. 2 Nylon suture, with welding of the suture ends using sonic energy. All loops were created over the same dowel. Loops were cycled between 10N and 45N for 200 cycles, followed by a failure test. Loop elongation and ultimate failure load were compared between welded sutures and both materials using a 2-way analysis of variance., Results: There were no differences in loop elongation for the welded Nylon sutures compared to EB Roeder and EB Duncan knots, although EB Weston knots had significantly less loop elongation (P < .05). Loop elongation was significantly lower with FW than with EB (P < .001). For maximum failure load, there were no differences between the various EB loops. Welded loops demonstrated similar maximum failure loads to EB Roeder and EB Duncan knots, but were lower than EB Weston knots. Overall, the FW knots were significantly stronger than the EB groups (P < .001 for all comparisons)., Conclusions: A novel method to simplify the knot tying procedure by welding the suture ends demonstrated mechanical properties generally similar to No. 2 Ethibond. This method provides: (1) surgical advantages by eliminating knot tying; (2) a quick and easy locking mechanism; and (3) a low profile that eliminates high-profile knots. However, it is not clear whether the lower stiffness or the lower failure load may detract from these potential benefits compared to constructs with greater stiffness., Clinical Relevance: The suture welding technique generally behaved in a manner similar to that of Ethibond suture loops, although the difficulty of tying arthroscopic knots was eliminated.

Background: Allograft anterior cruciate ligament reconstruction provides benefits such as earlier return to activities and less pain, but concerns remain regarding potential infection and biomechanical stability., Hypothesis: There is no difference in biomechanical properties of soft tissue allografts treated with the Biocleanse tissue sterilization process compared with irradiated and fresh-frozen allografts., Study Design: Controlled laboratory study., Methods: Thirty-six tibialis anterior allografts were equally divided between Biocleanse, irradiated, and fresh-frozen groups. Grafts were measured for cross-sectional area and looped over a smooth rod with the free sutured ends of the graft fixed in custom clamps. Specimens were tensioned to 10 N for 2 minutes and then loaded between 50 and 300 N for 1000 cycles followed by a failure test. Data for creep (mm); stiffness (N/mm) at cycles 1, 10, 100, and 1000; failure load (N); and failure stress (MPa) were compared with a one-way analysis of variance (P < .05)., Results: There were no statistically significant differences in creep between groups. Sterilized groups (irradiated = 144.7 +/- 17.7 N/mm and Biocleanse = 146.5 +/- 28.2N/mm) were significantly stiffer during the first cycle than the fresh-frozen group (117.8 +/- 15.7 N/mm, P < .005) without statistically significant differences for subsequent cycles. There were no differences between groups for either failure load (fresh-frozen = 1665 +/- 291.3 N, irradiated = 1671.9 +/- 290.2 N, Biocleanse = 1651.6 +/- 377.4 N) or failure stress., Conclusion: Data for "time-zero" physiologic stiffness and failure loads indicate that the Biocleanse process does not adversely affect the biomechanical properties of the allograft material., Clinical Relevance: This novel sterilization technique may provide surgeons with potential allograft material with similar biomechanical properties to native tissue.

Purpose: To compare the fixation strength and radiographic motion of an anchor designed for intracortical (IC) fixation (FT Anchor, Arthrex, Naples, FL) with that of standard anchors used for rotator cuff repair., Type of Study: In vitro human cadaveric biomechanical study., Methods: Four types of metallic suture anchors (8 per group) were randomly inserted into human cadaveric humeri using an IC anchor and 3 types of standard anchors. Anchors were inserted 45 degrees to the humeral head surface and 90 degrees to the rotator cuff line of action. Anchors were tested under physiologic loads for 500 cycles followed by a failure test. The number of cycles, failure mode, and failure load were recorded. Fluoroscopy was used to measure rotation and displacement of the anchor within the humeral head during testing. Data were analyzed using a 1-way analysis of variance with a correction for multiple comparisons., Results: There were no significant differences in anchor displacement or rotation measured by fluoroscopy after cyclic loading. Total construct displacement across anchors ranged from 4.9 to 7.8 mm, well beyond the 3-mm failure criterion reported in the literature. The IC anchor had a statistically significant greater failure load than the other devices. There was no significant difference in failure load between the other 3 anchors. The anchor had the greatest number of cycles to 3 mm of failure. This was not significantly different than the TwinFix anchor (Smith & Nephew, Andover, MA), but both values were significantly greater than both the Super Revo (Linvatec, Largo, FL) and Fastin RC (DePuy Mitek, Raynham, MA) anchors., Conclusions: Anchor motion accounted for about one third of total displacement of the suture/anchor construct. IC fixation anchors performed well compared with standard anchors in human cadaveric bone., Clinical Relevance: Fluoroscopic imaging showed both rotation and displacement of the anchor within the humeral head which may contribute to early gap formation after rotator cuff repairs.

Purpose: To compare a standard suture material with a newer material using multiple arthroscopic knot configurations and to evaluate the biomechanical performance of a new sliding-locking knot compared with 4 surgical standards., Type of Study: Controlled laboratory study., Methods: Five knots were evaluated (Weston, Tennessee, Duncan, SMC, and the new San Diego knot) using 2 suture materials, No. 2 Ethibond (Ethicon, Somerville, NJ) or No. 2 Fiberwire (Arthrex, Naples, FL). Eight samples were tested for each knot-suture configuration. Samples were pretensioned to 10 N and then loaded from 10 to 45 N for 1,000 cycles. Intact knots were loaded to failure., Results: Fiberwire had significantly higher load-to-failure (276 +/- 24 N) compared with Ethibond (111 +/- 13 N) (P < .001), although there was no significant difference as a function of knot configuration. Of the 40 Fiberwire knots, 3 failed by early slippage during cyclic loading and 8 slipped at very low tension during load-to-failure. None of the Ethibond knots and none of the San Diego knots failed by early slippage., Conclusions: Surface characteristics and suture construction affect the tendency for knot slippage., Clinical Relevance: Surgeons should understand the impact of handling characteristics, frictional properties, and ultimate failure load when selecting suture materials and knots for arthroscopic repair.

Background: Surgeons can control not only the angle but also the depth of suture anchor placement during arthroscopic rotator cuff repair, although the tendency may be to place suture anchors on the deep side to avoid damage from prominent anchor eyelets. However, little information is available regarding possible effects of suture anchor depth on construct failure mechanisms., Hypothesis: Anchor depth affects the mode of suture failure with physiologically relevant cyclic loads., Study Design: Controlled laboratory study., Methods: Metallic screw-in suture anchors loaded with No. 2 braided polyester sutures were inserted into the bovine infra-spinatus footprint with the eyelet proud, standard, or deep. Sutures were hand tied to create a closed loop. Constructs were cyclically loaded from 10 to 90 N and, if still intact at 500 cycles, taken to ultimate failure (maximum load)., Results: When clinical failure was defined as greater than 3-mm construct elongation, anchors placed with the eyelet deep experienced statistically earlier clinical failure via cutting of the suture through the bone (P < .02). However, anchors placed at this level did not experience catastrophic failure during cyclic loading. The standard and proud anchors experienced 3 mm of elongation at a greater number of cycles, but the suture material degraded at the anchor eyelet, and a majority of these constructs broke during cyclic physiologic loading. At failure testing, the deep anchors had a significantly increased failure load (164 N) compared to standard (133 N) (P < .04) and proud (113 N) anchors (P < .005)., Conclusion: Varying the depth of suture anchor insertion changes the mechanical properties and mode of failure of suture anchor constructs., Clinical Relevance: Surgeons should be aware of the effects of suture anchor depth and abrasive eyelet wear on construct failure during arthroscopic rotator cuff repair.

Purpose: Anchors that directly fix the rotator cuff to bone without using sutures may simplify the challenges associated with arthroscopic rotator cuff repair. This study compared a bioabsorbable screw fixation device to a standard suture anchor fixation method., Type of Study: Randomized trial., Methods: A poly-L-lactide acid (PLLA), bioabsorbable screw anchor was compared with a metallic suture anchor loaded with No. 2 braided polyester suture in 12-week-old fresh-frozen bovine shoulders. Twelve specimens were randomly assigned to the 2 repair groups (6 per group). A 1 x 2-cm defect was created at the insertion site of the infraspinatus tendon. Two anchors were implanted 1 cm apart in the anatomic insertional area of the infraspinatus tendon. After preconditioning to 10 N, each construct was cycled between 10 and 180 N for up to a maximum of 2,500 cycles at a rate of 33 mm/second using a materials testing machine. The number of cycles to 5- and 10-mm gap formation at the repair site and mode of failure were recorded. Clinically, 10-mm gap formation defines complete fixation failure. Data were evaluated using an analysis of variance with significance set at P < .05., Results: Mattress suture fixation had significantly higher number of cycles to 10-mm failure compared with the PLLA device (P = .015). Failure occurred by tissue pullout in half the specimens and by device failure in the other half, without differences in failure modalities between groups., Conclusions: This anchor provides low-profile fixation of the rotator cuff and eliminates suture placement and knot tying during arthroscopic and mini-open cuff repair. However, these data suggest that this anchor may not perform adequately under cyclic loading conditions in patients during postoperative rehabilitation., Clinical Relevance: This bioabsorbable anchor may not provide sufficient fixation for rotator cuff repair in humans.

The malleolar attachment sites of the tibionavicular (TN), tibiocalcaneal (TC), posterior tibiotalar (PTT), anterior talofibular (ATF), and calcaneofibular (CF) ligaments of 3 cadaveric ankles were dissected. Standard and new radiographic projections of the ankle were obtained with the foot in different positions and various degrees of beam angulation. Simulated avulsion injuries related to these ligaments were created, and the visibility of these structures was assessed. Avulsion injuries of the TN ligament were better assessed in the plantar-flexed radiographs with lateral beam angulation. Standard projections were found to adequately depict avulsion fractures related to the TC and CF ligaments. Radiographs in external ankle rotation were best for evaluating injuries of the PTT ligament. Avulsion injuries related to the ATF ligament were best visualized in the plantar-flexed views with medial beam angulation. Modified radiographic projections of the ankle improve visualization of ligamentous structures of the malleoli and avulsion injuries related to those.

Fungal arthritis is a rare infection usually caused by Candida species. Candida parapsilosis has emerged as a new pathogen and has been implicated in several cases of fungal arthritis, mostly associated with a joint prosthesis or after arthrocentesis. We report an unusual case of fungal arthritis of the knee caused by this organism in a 38-year-old female kidney transplant recipient, who had no previous invasive procedures on her knee. Systemic and intraarticular antifungal therapy combined with surgical debridement proved to be an effective treatment of this clinically difficult condition. To our knowledge, this case is the first report of fungal arthritis caused by C. parapsilosis in a transplant recipient. The multimodality approach used in the treatment of this patient should be considered in similar forms of fungal arthritis in immunocompromised patients.

Purpose: To demonstrate the normal anatomy of the stabilizing structures of the lateral aspect of the knee and to investigate pathogenesis of the Segond fracture, with emphasis on the iliotibial tract (ITT) and anterior oblique band (AOB) of the fibular collateral ligament., Materials and Methods: Dissection of the region of the AOB, ITT, and lateral capsular ligament was performed in three cadaveric knees, with placement of gadopentetate dimeglumine-filled tubes along their course and tibial insertions. These knees, in addition to three nondissected knees, were studied with magnetic resonance (MR) imaging by using standard and specialized oblique planes. Specimen sectioning provided anatomic correlation. Retrospective review of radiographs and MR images in 17 patients with acute Segond fractures was performed, and the relationship between the fragment and the demonstrated lateral supporting structures of the knee was noted., Results: Anatomic dissection and MR imaging of the cadaveric knees demonstrated a broad tibial insertion of the ITT, with fibers extending posterior to the Gerdy tubercle. A firm band of tissue, the AOB, extended from the fibular collateral ligament to the midportion of the lateral tibia, the typical site of a Segond fracture. The lateral capsular ligament proved to be a mere thickening of the capsule, inserting at the lateral tibia. Clinical analysis of acute Segond fractures confirmed the frequent attachment of the ITT and AOB to the avulsed fragment., Conclusion: Anatomic and clinical findings suggest that fibers of the ITT and AOB are important factors in the pathogenesis of the Segond fracture.

Purpose: Nonablative thermal capsular shrinkage has been developed in an attempt to address the plastic capsule deformation thought to cause increased rates of recurrent instability following arthroscopic stabilization procedures. Although the temperature required to optimize collagen shrinkage is known, a safe depth of thermal penetration, in various locations about the shoulder capsule, has not been defined. The purpose of this study was to measure shoulder capsule thickness by quadrant and circumferentially from the glenoid to the humerus so that thermal energy in shoulder procedures can be more precisely applied to limit possible injury to pericapsular structures., Type of Study: This is an anatomic study using a cadaveric shoulder specimens., Materials and Methods: Soft tissue was dissected from 8 fresh cadaveric shoulders to isolate intact glenohumeral joint capsules. The humeral insertion was released and the capsule was cut into 6 longitudinal quadrants around the glenoid. The capsule specimens were then flash frozen and stored at -80 degrees C. Quadrant tissue was cut into longitudinal sections 14 to 16 microm wide and stained with hematoxylin and eosin. The specimens were then digitized under a dissecting microscope and measured using computer imaging software at approximately 4-mm intervals. Two-way analysis of variance (ANOVA) was performed on the measurements of the intact capsule specimens 2.5 cm off the glenoid. Humeral insertion data were recorded separately., Results: A total of 248 separate measurements were made throughout the capsule in 8 specimens. Capsular thickness increased from an average of 2.42 mm anteriorly to 2.80 mm in the inferior capsular pouch and again thinned to 2.22 mm posteriorly. Global shoulder capsule thickness ranged from 1.32 to 4.47 mm. When analyzed by position, from glenoid to humerus, a general thinning was noted with a mean thickness of 3. 03 mm at the glenoid to 2.17 mm at the humeral insertion. Two-way ANOVA showed a significant thickness variation along the specimen (P <.05), a nearly significant thickness variation with regard to quadrant (P <.03), and no significant interaction (P >.07) when applied to specimen measurements approximately 2.5 cm off the glenoid., Conclusions: The thickness of the shoulder capsule ranges from 1.32 to 4.47 mm, with a significant thinning laterally from the glenoid to the humerus. Further, capsule thickness ranges from 2.76 to 3.18 mm in the regions in closest proximity to the axillary nerve. These data may help determine the proper amount of thermal penetration necessary when performing shrinkage procedures and provide safety guidelines to limit the depth of thermal penetration to avoid possible injury to pericapsular structures.